The structural foundation of many common vehicle designs is the frame. The frame can be made of multiple frame members, often formed of metals such as steel. Additional vehicle components, such as the engine, body, power train, and interior, are ultimately connected to and supported by the frame. Some vehicles include a unibody design, in which the frame is integrated with the body.
Because the frame forms the structural foundation of a vehicle, it is typically very strong and designed to withstand large amounts of stress. Some frames, however, are also designed with intentional weaknesses. For example, automobile frames are commonly designed to include a crumple zone toward the front or rear of the vehicle. The crumple zone operates to deform during a collision to absorb some of the impact and thereby lessen the impact on passengers.
Due in part to the complex shapes of many vehicle frames, as well as to the wide variety of different vehicle frames, it can be difficult to determine whether a vehicle's frame has been bent from an original configuration. Such deformation, however, can have adverse consequences, such as reducing the structural integrity of the vehicle, or increasing wear on vehicle components.
Once a vehicle frame has been deformed, it can sometimes be repaired by bending the frame back to the proper position. However, due to the wide variety of different vehicle frames, as well as the complex shape of most vehicle frames, it can be difficult to determine how to adjust the frame to return the frame to the proper position.